This invention relates to a process and apparatus for the collection of volatile vapors in and around mechanical equipment for disposal in a safe manner. More particularly, the preferred embodiment is directed to a process and collection system for withdrawing and disposing of volatile organic vapors from rotating or reciprocating equipment, and more specifically from one or more pumps handling volatile organic compounds at one or multiple locations. Volatile organic compounds, or "VOC", are known to be precursors to the formation of ozone in the atmosphere. Among the many types of compressors and mechanical equipment used in processing and handling vapors and liquids in the hydrocarbon processing industries, the centrifugal and reciprocating pumps have been identified as one source of VOC emissions. Means for sealing the rotating shaft in a centrifugal pump housing have been the subject of much attention in pursuit of a solution to the VOC emission problem. A vapor emission control system for centrifugal pumps is disclosed in U.S. Pat. No. 4,722,662, issued Feb. 2, 1988 to Morgan. U.S. Pat. No. 4,722,662 describes a centrifugal pump removable cover disposed between the seal housing portions of the pump casing and the outboard bearing housing portions of the pump, which cover has vapor absorption filters supported thereon and in fluid flow communication with the pump fluid leakage collection spaces formed between the pump shaft seal housing and the pump shaft bearing housing.
Another approach to handling VOC emissions from centrifugal pumps involves the use of a fluidic seal displaced between the shaft seals of a centrifugal pump. Fluidic means for sealing pumps are costly and still do not provide a leakage level low enough for compliance with proposed government emission limits.
A number of vapor recovery systems for the pumping of volatile organic compounds have also been taught. A vapor recovery system disclosed in U.S. Pat. No. 4,058,147 issued Nov. 15, 1977 to Stary et al teaches a recovery system for withdrawing flammable vapors from the vicinity of a dispensing nozzle at a service station or the like, and disposing of the vapors in a combustor.
A mobile emission recovery apparatus disclosed in U.S. Pat. No. 5,050,603, issued Sep. 24, 1991 to Stokes et al teaches an inline blower for maintaining flow of VOC emissions through the apparatus, and an internal combustion engine adapted to use light hydrocarbon as fuel. It is important in the teaching of Stokes that the feed to the engine not exceed the lower explosion limit of the vapor.